Breech lock for machine guns



A. H. G. FOKKER.

I BREECH LOG-K FO'R MACHINE GUNS- APPLICATION FILED SEPT. I. 1920.

1 126,855 1 Patented Aug. 22, 1922.

111/! far ANTHONY HERMAN GERARD FOKKER, OF AMSTEBDAIVI, NETHERLANDS.

BEEEGH LOOK FOR- MAGHINE GUNS.

Application filed September 1, 1920.

) useful improvements in Breech Locks for Machine Guns (for which. i have filed application in Germany. No. 310,179, filed Feb. let, 1918), of which the following a specification.

The type of machine c'un in which the breech block. the movei'nent of which places a cartridge in position andv operates the firing pin. is given a reciprocating movement by mechanical n'ieans. such as a. rotating crank, instead of being' returned to the cocked position by the recoil of the explosion in the gun, is well known.

The present invention is a new and useful improvement in the means of holding); the

. breech block firmly in position while the shot is tired, by means of independent lockino' members which transmit the pressure fired, directly to the frame or the gun instead of to the crank i'nechauism which reci 'n-ocates the breech block.

The accompanying drawing: illustrates diagrammatically the construction of the gun mechanism wh ch forms the subject of this lEiYPllillOI].

Fine. 1. and 2 respectively show a vertical and. horizontal section of the gun mechanism. and

3 is a cross section on the line A.B Fiji. 1.

The operatingcrank A. carries. in addition. to the journal by which. the breech block is reciprocated. through the medium of a connecting rod. a projection on each side in which a cam faced groove B is cut. This groove ei'igages the rear ends of the locking' levers which are pivoted at F on the frame of the {11111. Part of one rotation of the operating crank A moves the breech block forward to the firing position after which the remainder of the rotation causes the locking; levers (I by means of the grooves B to pivot by means of the shape of the grooves B into such a. position that the shoulders formed on the forward ends of the locking levers C engage with the breech block D and'hold it firmly in position while the shot is fired. The arrangement is such that the locking levers are subjected only Specification of Letters Patent.

ting on the bieech block, when the shot Patented Aug. 22, 1922.

Serial No. 407,540.

to a compression and not to a bending stress. The means by which part of the rotation of the crank brings the breech block into position and the remainder only moves the lockin levers, forms the subject of my copendin application for Letters Patent of the Unitec States. Serial No. 07,539, filed September 1. 1920. The locked position is maintained until the shot has left the barrel, whereupon the locking levers are returned by the continued rotation of the crank and the shape f the grooves B to their initial position, thus releasing" the breech block which is brought back to the cocking position by the continual rotation of the crank asdescribed in application No. 407,539, above identified. To prevent the locking levers from moving by themselves or being moved by vibration, when the ends of the lovers have left the groove B, small springs E hold the front ends of the levers back against the walls (lr of the frame of the gun. It should be noted that by means of the invention described in my copending application hereinl'iefore referred to, the rotation of the iu'un'atilrc crank remains continuous and uniform throughout the operations described.

Having now particularly described and ascertained the nature of my said invention and. in what manner the same is to be performed. I declare that what I claim is 1. In a breech block mechanism for machine guns. a rotating crank operatinp the breech block, locking levers pivotally mounted upon the frame of the gun, actuated by the rotation of the said crank. so as to lock the breech block in position during the firing of the cartridge.

In a breech block mechanism for machine guns, arotating crank having cam faced. grooves. locking levers, subject to com ANTHONY HERMAN GERARD FOKKER.

lVitnesses C. PORTER, H. G. KoYPERs. 

